By Mariam Khan A celebrity chef has said that we’ve all been making the classic mashed potatoes wrong all this time. Christmas may be over but if you live in a Sunday roast dinners house then you need to make sure your mashed potatoes are creamy and smooth and if you’ve ever struggled with that then one celebrity chef has a few tips that can help you. The chef shared his top tips for making perfectly smooth and creamy mashed potatoes that will have your family asking for seconds and your guests asking for the recipe. Whilst this year’s celebrations may be over, top celebrity chef Andrew Rudd h…